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Brews & Views Bulletin Board Service * Brews and Views Archive 2003 * December 9, 2003 * Dry yeast: 2pks vs 1pk < Previous Next >

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The Beav (24.217.13.27)
Posted on Sunday, November 23, 2003 - 06:16 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

In Palmer's book, he recommends to use 2 packages if using dry yeast. Is this a common practice? Is this just insurance that you will have an active fermentation?

As you can tell, I'm still learning the basics.

Beav
 

David Woods (67.242.92.101)
Posted on Sunday, November 23, 2003 - 06:30 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I would say it depends on your Original Gravity or OG of the wort. Anything up to 1.045 - 1.050 I would say that 1 pk would be enough. Any higher, and 2 pks would definetly help getting the gravity down towards where you want it to end.

Aereation will also help, but that's a whole other question.

I can hear Bill P's mantra right now...

David
 

Bill Pierce (24.141.63.119)
Posted on Sunday, November 23, 2003 - 06:48 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I think a second pack of dry is cheap insurance against underpitching, but I agree that one is usually sufficient for lower gravity beers.
 

Walt Fischer (24.221.196.114)
Posted on Sunday, November 23, 2003 - 06:54 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

What?!
No 6 gallon starter with heavy aereation?!
Are you not feeling good Bill?
Did you not have the cut n paste ready?

heh
Walt
 

Bill Pierce (24.141.63.119)
Posted on Sunday, November 23, 2003 - 07:09 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Walt, the population is reasonably high in a large (11-15 gram) packet of dry yeast. There can be as many as 200 billion cells, which is close to the optimum pitching rate for a batch of 1.045 O.G. ale, for example. Of course, that's not even starter wort for you.
 

Tom Gardner (66.82.182.25)
Posted on Sunday, November 23, 2003 - 07:37 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

They have recently enlarged the packages of Danstar yeast to 11g, so which size are we talking about?

Walt, for your 55 gallon batches I think the suggestion of a 6 gallons starter would be a good idea!
 

Fredrik (213.114.44.229)
Posted on Sunday, November 23, 2003 - 07:56 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

For my xmas beer I even used 3 packs of nottingham for 5 gallons @ 1.046. But that was because

1) it was the low end of the temp range
2) I had alot of honey

Judging from the results only, I could not see that this was near too much.

I didn't bother aerating much. Just some splashing, but no pumps or oxygenators.

I am still trying to understand where all the oxygen goes, but it seems clear that a big part the oxygen you add to the wort isn't used for what you think (sterol synthesis). This makes me wonder what the heck it's used for. So far I have only made normal gravity batches, for to test some ideas would like to try and make a high gravity beer.

How big OG do you guys think I should have in order to normally run into problems of underaeration with normal pitching rates?

The experiment would be to oxygenate the starter but make sure there is basically no oxygen in the wort (full boil). The idea is that oxygenating the starter with a good pitchin rate is enough, and that oxygenation the wort isn't necessary. So far I can't tell because I've made only like 1.045 kind of beers. And the "point" might be that alot of the oxygen added doesn't go where it's supposed to anyway. I wonder if there would be any flavour implications in this, set aside the attenuation which is only one issue?

/Fredrik
 

Chuck Denofrio (64.135.203.37)
Posted on Monday, November 24, 2003 - 01:46 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

When I started, I would buy a kit, boil it and after cooling pour in 1 pack of dry yeast and it would work. The point being, the yeast had to rehydrate and develope in the wort with no help from me. From what I read, as the sugar goes up so must the yeast. So try 100 points with no O2. As you have said, "if the outcome is known, what fun is that?"
 

Jared Cook (24.1.247.22)
Posted on Monday, November 24, 2003 - 02:50 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

The idea is that oxygenating the starter with a good pitchin rate is enough, and that oxygenation the wort isn't necessary.

That, Fredrik, is exactly what several British breweries do. Do a search on the HBD mailing list archives for Tracy Aquilla and yeast respiration. Someone asked that exact question, and his response was something on the lines of "hey, there's someone who's actually thinking."

He wrote an article for Brewing Techniques about oxygen consumption of yeast. It was titled something like "Debunking the myths of yeast respiration".
 

Fredrik (213.114.44.229)
Posted on Monday, November 24, 2003 - 07:09 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Mmm 1.100 is in Walts regions :)

Interesting Jared! I'll try that search. Actually I know that last article, it was one of the first I read back half a year ago.

/Fredrik
 

Drew Avis (209.226.137.107)
Posted on Monday, November 24, 2003 - 03:28 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I'd say 15-20 gr / 25L for ales, 20-25 gr / 25L for lagers (depending on ferm temp and OG) - so yes, 2 packs is almost always a good idea.
 

Adam W (128.125.6.113)
Posted on Monday, November 24, 2003 - 08:18 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Aerating or oxygenating with Nottingham is irrelavant (only on the first pitch) because it already has been loaded with an excess of unsaturated fatty acids.

Direct from the Danstar website:

"It is unnecessary to aerate wort."
 

Bill Pierce (24.141.63.119)
Posted on Monday, November 24, 2003 - 08:48 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Adam, I'd like to see more explanation of that claim. Is Lallemand referring to wort into which their yeast is pitched or to all wort in general?
 

Adam W (128.125.6.113)
Posted on Monday, November 24, 2003 - 10:32 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Only on the first pitch of their yeast. See the Nottingham pdf avaiable on their website.
 

Fredrik (213.114.44.229)
Posted on Tuesday, November 25, 2003 - 06:18 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I don't konw exactly the procedure when they manufacture dry yeast, but *if* as I think the internal cell reserves of glycogen as well as oxygen derived compounds is full (sterols and UFAs) I would find it sensible to think that adding oxygen to the wort isn't necessary. The reason would be that the live yeast is very healthy nutritionwise, and directly after pitching they simply doesn't need oxygen. Of course they could probably use some in the later stages (some 12-24 hours after pitching or something), but then the question is, is the wort oxygen added in the beginning still available to yeast at this time, or has it been used up for other purposes?

I think the difference here is the initial conditions and nutrition levels of yeast when pitched. I think the initial conditions determine the initial oxygen demand, which can vary from large (for a big fatigued yeast cake) to low or almost none for dry yeast. Where the oxygen demand for dry yeast is just very low, or actually ZERO, is hard to tell. That statement has to stand for Danstar. But on the other hand, even a non-aerated wort will probably contain a few ppm O2?

/Fredrik

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